• 한국제4기학회지
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• 제21권2호
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• pp.1-3
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• 2007

• 한국제4기학회지
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• 제17권2호
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• pp.167-168
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• 2003

The Upo wetland, the largest natural wetland in Korea, is located in Changnyeong-gun, Gyeongsannam Province ($35^{\circ}33'$ N, $128^{\circ}25'$ E), and 70 km upstream from the Nakdong River estuary. Unlike most other Korean wetlands that have been destroyed under the name of economic development, the Upo wetland has been able to preserve its precious ecosystem throughout the years. Thanks to increased public awareness about natural wetlands and environmental conservation, the Korean Ministry of Environment designated the Upo wetland an 'Ecological Conservation Area' on July 26th, 1997. On March 2nd of the following year, the Upo wetland (8.54 $\textrm{km}^2$) was designated a 'Protected Wetland' in accordance with the international Ramsar Treaty. A 4.49m long (from 9.73 to 5.24 m in altitude) UP-1 core ($35^{\circ}33'05"N$, $128^{\circ}25'17"E$), recovered in the marginal part of the Upo wetland, is divided into eight buried paleosol units of different ages on the basis of the abundance of color mottles and vertical color variations (Aslan et al., 1998). Radiocarbon datings suggested that the paleosol profile represent the last 5700 years. The entire section of the core was more or less subjected to pedogenetic processes, and shows very weak to moderate soil profile development. These Holocene paleosols are therefore regarded as synsedimentary soils of deluvium (deposits formed by floods) origin (Sycheva et al., 2003). Unit 1 to 5 paleosols are generally silt-rich and exhibit moderate profile development. The boundaries between the units are somewhat distinguishable, but not so clear cut. This is due to variable repeated combination of accumulation, denudation and soil forming processes within various periods. Mottle textures gradually decrease in abundance with increasing clay content in Unit 6, which results in weak profile development. The lower boundary of Unit 6 lies around about 2000 yrBP, the beginning of Subatlantic in Korea (Kim et al., 2001). Abrupt sediment textural change is detected in Unit 7, which is interpreted to indicate the human activities on the Upo wetland. Unit 8 represents the recent soil forming processes. The preliminary results of this ongoing study imply the primary factor for pedogenetic processes is the water table fluctuations related to the sedimentary textures like grain size distributions, and the geomorphological stability of the Upo wetland.o wetland.

• 한국습지학회지
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• 제12권2호
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• pp.1-12
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• 2010

본 연구에서는 비교적 도심 가까이에 위치하는 부산광역시 금정산 산지습지의 지질학적 특성을 규명하였다. 야외조사와 실내분석에 의해서 금정산 산지습지의 지형, 지질, 구조지질학적 특성, 습지로부터의 거리에 따른 암석의 강도, 습지의 토양단면, 토양의 화학적 특성을 파악하였다. 금정산 습지의 기반암은 각섬석화강암이며, 습지 주변의 각섬석화강암과 유문암질암의 절리의 주향은 대체로 남북방향, 동서방향, 북동-남서방향이며 $60^{\circ}$ 이상의 급한 절리 경사각을 가지고 있다. 또한 습지에 가까울수록 암석의 강도가 낮아지고 풍화도는 높아짐을 알 수 있다. X선 회절분석에 의하면, 습지 토양시료에는 카올리나이트, 몬모릴로나이트, 깁사이트가 나타나며, 이는 장석의 풍화산물임을 지시한다. 습지 토양의 단면은 지표에서부터 O, A, B, C층의 순서로 놓여 있으며, 유기물 함량은 토양의 심도가 깊어질수록 감소하는 경향성을 보이고 있다. 또한 습지 토양의 무기물 성분 중 $K^+$와 $Na^+$의 농도가 높게 나타나며, 이는 장석의 풍화에서 유래함을 지시한다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2002년도 암반역학위원회 학술세미나 논문집
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• pp.103-114
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• 2002

Stability of cut-slope is considered to have a deep relationship with rock types since rock has its own engineering and geological characteristic such as shear strength, durability, weathering profile, geological structures. Therefore, analysis of geological and engineering characterisics of rock mass is essential for the evaluation of rock slope stability This paper introduces the statistical data of slope failure cases which was collected from highway slopes constructed in sedimentary rock mainly of shale in Ky ng-sang Basin. Primary failure feature in this area is planar failure along the bedding regardless of slope geometry. Even a disasterous slope failure case due to the thick clay layer between the beddings was reported. Failures and rock fall were reported to ocurred frequently after the completion of cutting due to the weathering, so long-term slope stability should be considered as a important factors in design.

• Geomechanics and Engineering
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• 제14권6호
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• pp.545-552
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• 2018

Blast-induced ground vibrations by a significant amount of explosives may cause many problems for mining slope stability. Geological discontinuities have a significant influence on the transmission of dynamic pressure of detonation and according to their position relative to the slope face may have damaging or useful impacts on the slope stability. In this study, the effect of geological discontinuities was investigated by modelling a slope with geological discontinuities through applying the dynamic pressure in three-dimensional discrete element code (3DEC). The geological discontinuities in four states that generally apperceived in mine slopes are considered. Given the advantages of the pressure decay function defined by some researcher, this type of function was used to develop the pressure-time profile. The peak particle velocities (PPV) values were monitored along an axis by utilization of Fish programming language and the results were used as an indicator to measure the effects. As shown in the discontinuity-free model, PPV empirical models are reliable in rocks lacking discontinuities or tightly jointed rock masses. According to the other results, the empirical models cannot be used for the case where the rock mass contains discontinuities with any direction or dip. With regard to PPVs, when the direction of discontinuities is opposite to that of the slope face, the dynamic pressure of detonation is significantly damped toward the slope direction at the surface of discontinuities. On the other hand, when the discontinuities are horizontal, the dynamic pressure of detonation affects the rock mass to a large distance.

• 한국제4기학회지
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• 제20권1호
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• pp.39-50
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• 2006

거창의 정장리 유적은 거창분지에 포함되며 황강천상류 하안단구면 위에 분포한다. 정장리의 유적발굴 지내에는 하성퇴적층이 제2지구 2트랜치 북면과 남면에 잘 발달하여 있다. 본 연구의 목적은 정장리 일대의 하성퇴적층의 산상, 입도분석 및 화분분석을 통하여 퇴적층 환경과정을 해석하는데 있다. 연구결과 하성퇴적층의 상부에는 약 $25,000{\sim}30,000$년전의 토양쐐기 구조가 발달한 고토양층이 분포하며, 하부로 가면서 적갈색 니사질층, 유기질 니층 및 사력층이 분포하고 있다. 대표단면인 남벽토층의 유기질 니층에 대한 화분연구 결과, 단면 하부에 초본식물 화분대, 상부에 오리나무-참나무-소나무 화분대가 각각 발견되었다. 형성시기로 볼 때 하부 화분대는 약 80,000 - 70,000년전의 아빙기, 상부 화분대는 약 60,000-50,000년전 사이에 형성된 것으로 해석된다. 정장리 유적에 나타나는 화분대는 활엽수/침엽수 혼유림이 우세하며, 당시에는 온냉(cool temperate) 습윤기후가 우세하였던 것으로 추정된다.

• Earthquakes and Structures
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• 제5권2호
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• pp.161-205
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• 2013

We study seismically induced, anti-plane strain wave motion in a non-homogeneous geological region containing tunnels. Two different scenarios are considered: (a) The first models two tunnels in a finite geological region embedded within a laterally inhomogeneous, layered geological profile containing a seismic source. For this case, labelled as the first boundary-value problem (BVP 1), an efficient hybrid technique comprising the finite difference method (FDM) and the boundary element method (BEM) is developed and applied. Since the later method is based on the frequency-dependent fundamental solution of elastodynamics, the hybrid technique is defined in the frequency domain. Then, an inverse fast Fourier transformation (FFT) is used to recover time histories; (b) The second models a finite region with two tunnels, is embedded in a homogeneous half-plane, and is subjected to incident, time-harmonic SH-waves. This case, labelled as the second boundary-value problem (BVP 2), considers complex soil properties such as anisotropy, continuous inhomogeneity and poroelasticity. The computational approach is now the BEM alone, since solution of the surrounding half plane by the FDM is unnecessary. In sum, the hybrid FDM-BEM technique is able to quantify dependence of the signals that develop at the free surface to the following key parameters: seismic source properties and heterogeneous structure of the wave path (the FDM component) and near-surface geological deposits containing discontinuities in the form of tunnels (the BEM component). Finally, the hybrid technique is used for evaluating the seismic wave field that develops within a key geological cross-section of the Metro construction project in Thessaloniki, Greece, which includes the important Roman-era historical monument of Rotunda dating from the 3rd century A.D.

• 대한토목학회논문집
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• 제36권5호
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• pp.891-901
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• 2016

측상구조를 갖는 다변성 지반에서 시행된 3개소 24회의 시험발파로부터 획득한 발파진동 데이터를 지층단면도와 연계하여 제어가 불가능한 지반 특성으로 인한 발파진동 영향을 분석하였다. 화산쇄설층인 클링커층이 불규칙하게 반복되는 층상구조에 대한 발파공학적 경험과 자료의 부족 등으로 충분한 검토가 이루어지지 않은 비효율적인 발파가 이루어지고 있다. 시험발파 지역 내 클링커층의 N값은 매우 다양한 범위로 나타나 정량화하기 매우 어렵다. 그리고 현장의 전체 발파진동 추정식(SRSD)은 감쇠지수 n의 절대값이 설계지침보다 작게 나타나 발파진동이 멀리 전파되었으며, 발파진동상수 K와 감쇠지수 n이 상대적으로 매우 작은 값을 보인 시험발파. 1의 진동특성을 지층단면도로부터 유추한 결과, 연암층 하부에 접한 클링커층 인근까지 발파천공이 진행되어 발파 시 하부에 넓게 분포하고 있는 클링커층으로 폭발 가스압이 손실되었을 것으로 판단된다. 이로 인해 암파쇄량도 절반정도로 감소하였다. 그리고 현장의 주주파수 대역은 일반적인 구조물의 고유 주파수 대역과 유사한 저주파수 대역으로 확인되었다.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 1999년도 준설 및 환경매립에 관한 학술세미나
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• pp.15-31
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• 1999

The Pusan Clay is analyzed hereafter from a point of view of mineralogy and microstructure. Results indicate that the Pusan Clay is basically illitic in nature and that the soil microstructure reveals some characteristics which could be responsible for its brittle behavior as observed from sample disturbance. The overall analysis would tend to consider that the Pusan Clay profile analyzed here shows mechanical properties similar to well structured soils or so-called cemented soils.

• 한국지반공학회지:지반
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• 제10권4호
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• pp.29-38
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• 1994

공내하향 탄성파시험(downhole seismic tests) 결과를 해석하는 새로운 방법을 소개하였다. 이 방법은 역산이론(inverse thery)에 근거 하며, 직접산출법(direct measurements)과 간접산 출법(indirect measurements)과 같은 기존 방법으로는 불가능한 정도의 자세한 탄성파 속도 프로파일(profile)을 얻을 수 있다. 더욱이, 이 방법은 속도 프로파일의 신뢰도를 평가 할 수 있는 장점이 있다. 지반구조가 서로 다른 5개소의 현장에서 이 방법의 적용성을 검증하였다.